Impact of the Addition of Antithymocyte Globulin to Post-Transplantation Cyclophosphamide in Haploidentical Transplantation with Peripheral Blood Compared to Post-Transplantation Cyclophosphamide Alone in Acute Myelogenous Leukemia: A Retrospective Study on Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The use of haploidentical hematopoietic cell transplantation (haplo-HCT) with peripheral blood stem cells (PBSCs) to treat acute myelogenous leukemia (AML) is increasing. We explored whether the addition of antithymocyte globulin (ATG) to post-transplantation cyclophosphamide (PTCy) allows better outcomes compared with PTCy alone in haplo-HCT with PBSCs (haplo-PBSCT). We included 441 adult patients undergoing a first haplo-PBSCT for AML in first or second complete remission; graft-versus-host disease (GVHD) prophylaxis contained either PTCy alone (n = 374) or ATG plus PTCy (n = 67), in addition to cyclosporine A (CsA) and mycophenolate mofetil (MMF) as other immunosuppressive agents. All transplantations were performed between 2011 and 2019. No major imbalances were observed between the 2 groups. For both groups, the median patient age was 56 years, and the median year of haplo-PBSCT was 2017. Most patients received a reduced-intensity conditioning regimen (57% in the PTCy group and 61% in the ATG+PTCy group; P = .54). The median follow-up was 19 months in the PTCy group versus 15 months in the ATG+PTCy group (P = .59), and the rate of neutrophil engraftment in the 2 groups was 97% and 98%, respectively. In univariate analysis, there were no statistical differences in transplantation outcomes between the 2 groups. In multivariate analysis, ATG+PTCy was associated with a lower risk of chronic GVHD compared with PTCy alone (hazard ratio, .46; 95% confidence interval, .23 to .93; P = .03). No between-group differences in the other transplantation outcomes were seen. In haplo-PBSCT, the addition of ATG to PTCy (with CsA and MMF) is feasible and better at preventing chronic GVHD and is associated with survival and transplantation outcomes comparable to those with PTCy alone, without increasing transplantation toxicity, mortality, or relapse incidence.

Total body irradiation plus fludarabine versus thiotepa, busulfan plus fludarabine as a myeloablative conditioning for adults with acute lymphoblastic leukemia treated with haploidentical hematopoietic cell transplantation. A study by the Acute Leukemia Working Party of the EBMT.

Optimal conditioning for adults with acute lymphoblastic leukemia (ALL) treated with haploidentical hematopoietic cell transplantation (haplo-HCT) and post-transplant cyclophosphamide has not been established so far. We retrospectively compared outcomes for two myeloablative regimens: fludarabine + total body irradiation (Flu-TBI, n = 117) and thiotepa + iv. busulfan + fludarabine (TBF, n = 119). Patients transplanted either in complete remission (CR) or with active disease were included in the analysis. The characteristics of both groups were comparable except for patients treated with TBF were older. In univariate analysis the incidence of non-relapse mortality (NRM) at 2 years was increased for TBF compared to Flu-TBI (31% vs. 19.5%, p = 0.03). There was a tendency towards reduced incidence of relapse after TBF (p = 0.11). Results of multivariate analysis confirmed a reduced risk of NRM using Flu-TBI (HR = 0.49, p = 0.03). In the analysis restricted to patients treated in CR1 or CR2, the use of Flu-TBI was associated with a decreased risk of NRM (HR = 0.34, p = 0.009) but an increased risk of relapse (HR = 2.59, p = 0.01) without significant effect on survival and graft-versus-host disease. We conclude that for haplo-HCT recipients with ALL, Flu-TBI may be preferable for individuals at high risk of NRM while TBF should be considered in cases at high risk of relapse.

Post-transplant cyclophosphamide in one-antigen mismatched unrelated donor transplantation versus haploidentical transplantation in acute myeloid leukemia: a study from the Acute Leukemia Working Party of the EBMT.

Whether to choose Haploidentical (Haplo) or one-antigen mismatched unrelated donor (1Ag-MMUD) hematopoietic cell transplantation (HCT) with post-transplant cyclophosphamide (PTCy) remains an unanswered question. We compared PTCy- Haplo-HCT to PTCy-1Ag-MMUD-HCT for acute myeloid leukemia (AML) in complete remission (three groups: 1Ag-MMUD using peripheral blood (1Ag-MMUD-PB; n = 155); Haplo using bone marrow (Haplo-BM; n = 647) or peripheral blood (Haplo-PB; n = 949)). Haplo-BM and Haplo-PB had a higher non-relapse mortality (NRM) compared to 1Ag-MMUD-PB (HR 2.28, 95% CI 1.23-4.24, p < 0.01; HR 2.65, 95% CI 1.46-4.81, p < 0.01, respectively). Haplo groups experienced a lower leukemia-free survival (LFS) compared to 1Ag-MMUD-PB (Haplo-BM: HR 1.51, 95% CI 1.06-2.14, p = 0.02; Haplo-PB: 1.47, 95% CI 1.05-2.05, p = 0.02); overall survival (OS) was also lower in Haplo-HCT (Haplo-BM: HR 1.50, 95% CI 1.02-2.21, p = 0.04; Haplo-PB: HR 1.51, 95% CI 1.05-2.19, p = 0.03). No differences were observed for graft-versus-host/relapse-free survival (GRFS) and relapse incidence (RI). Haplo-BM was associated with a lower risk of grade III-IV acute graft-versus-host disease (GVHD) (HR 0.44, 95% CI 0.24-0.81; p < 0.01), while no statistical differences were observed between groups for grade II-IV aGVHD and for cGVHD. Use of PTCy in 1Ag-MMUD-HCT is a valid alternative to consider when using alternative donors. Larger analysis of 1Ag-MMUD versus Haplo-HCT are warranted.

Measurable residual disease status and outcome of transplant in acute myeloid leukemia in second complete remission: a study by the acute leukemia working party of the EBMT.

Measurable residual disease (MRD) prior to hematopoietic cell transplant (HCT) for acute myeloid leukemia (AML) in first complete morphological remission (CR1) is an independent predictor of outcome, but few studies address CR2. This analysis by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation registry assessed HCT outcomes by declared MRD status in a cohort of 1042 adult patients with AML CR2 at HCT. Patients were transplanted 2006-2016 from human leukocyte antigen (HLA) matched siblings (n = 719) or HLA 10/10 matched unrelated donors (n = 293). Conditioning was myeloablative (n = 610) or reduced-intensity (n = 432) and 566 patients (54%) had in-vivo T cell depletion. At HCT, 749 patients (72%) were MRD negative (MRD NEG) and 293 (28%) were MRD positive (MRD POS). Time from diagnosis to HCT was longer in MRD NEG than MRD POS patients (18 vs. 16 months (P < 0.001). Two-year relapse rates were 24% (95% CI, 21-28) and 40% (95% CI, 34-46) in MRD NEG and MRD POS groups (P < 0.001), respectively. Leukemia-free survival (LFS) was 57% (53-61) and 46% (40-52%), respectively (P = 0.001), but there was no difference in terms of overall survival. Prognostic factors for relapse and LFS were MRD NEG status, good risk cytogenetics, and longer time from diagnosis to HCT. In-vivo T cell depletion predicted relapse.

Post-transplantation cyclophosphamide GvHD prophylaxis after hematopoietic stem cell transplantation from 9/10 or 10/10 HLA-matched unrelated donors for acute leukemia.

HLA-matching largely contributes to unrelated donor hematopoietic cell transplantation (UD-HCT) success but, due to the selective deletion of alloreactive T-cells, post-transplantation cyclophosphamide (PTCy) could modulate its negative impact on outcomes. We retrospectively compared acute leukemia patients receiving 10/10 or 9/10 HLA allele-matched UD-HCT with PTCy-GvHD prophylaxis between 2010 and 2017, reported to EBMT registry. The 100-day incidence of grade ≥2 and grade ≥3 aGvHD were comparable for 10/10 and 9/10 UD (28% versus 28%, p = 0.8 and 10% versus 8%, p = 0.5, respectively). The 2-year cGvHD and extensive cGvHD were similar between 10/10 and 9/10 UD (35% versus 44%, p = 0.2 and 21% versus 20%, p = 0.6, respectively). The 2-year nonrelapse mortality was 20% after 10/10 and 16% after 9/10 UD-HCT (p = 0.1). Relapse incidence at 2-year was 24% for 10/10 and 28% for 9/10 UD-HCT (p = 0.4). Leukemia-free survival at 2-year was the same for 10/10 and 9/10 UD (56 and 56%, p = 0.6, respectively), with comparable overall survival (62 and 59%, p = 0.9, respectively). Multivariate analysis showed no effect of HLA-matching on outcomes. An advanced disease status and patient disability remained the most important factors portending a worse survival. PTCy could alleviate the detrimental effect of HLA-allele mismatching in UD-HCT, potentially expanding the donor pool for acute leukemia patients.

Determinants of survival in myelofibrosis patients undergoing allogeneic hematopoietic cell transplantation.

We aimed to evaluate the determinants of survival in myelofibrosis patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) and to describe factors predicting the main post-HCT complications. This retrospective study by the European Society for Blood and Marrow Transplantation included 2916 myelofibrosis patients who underwent first allo-HCT from an HLA-identical sibling or unrelated donor between 2000 and 2016. After a median follow-up of 4.7 years from transplant, projected median survival of the series was 5.3 years. Factors independently associated with increased mortality were age ≥ 60 years and Karnofsky Performance Status <90% at transplant, and occurrence of graft failure, grades III-IV acute graft-vs.-host disease (aGVHD), and disease progression/relapse during follow-up. The opposing effects of chronic graft-vs.-host disease (GVHD) on non-relapse mortality and relapse incidence resulted in a neutral influence on survival. Graft failure increased in unrelated donor recipients and decreased with myeloablative conditioning (MAC) and negative donor/recipient cytomegalovirus serostatus. Risk of grades III-IV aGVHD was higher with unrelated donors and decreased with MAC. Relapse incidence tended to be higher in patients with intermediate-2/high-risk DIPSS categories and to decrease in CALR-mutated patients. Acute and chronic GVHD reduced the subsequent risk of relapse. This information has potential implications for patient counseling and clinical decision-making.

WT1 Gene Expression in Peripheral Blood Before and After Allogeneic Stem Cell Transplantation is a Clinically Relevant Prognostic Marker in AML - A Single-center 14-year Experience.

BACKGROUND: This work summarizes our experience with WT1 monitoring before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). PATIENTS AND METHODS: The expression of WT1 gene was measured by real-time polymerase chain reaction in peripheral blood according to the European Leukemia Net recommendations. Between May 2005 and August 2019, we analyzed 147 consecutive patients with acute myeloid leukemia with high WT1 expression at diagnosis, transplanted in first (CR1) or second (CR2) complete remission. RESULTS: At the time of allo-HSCT, 107 patients had WT1-normal expression (WT1 ≤ 50 copies), and 40 patients had WT1-high expression. The median follow-up was 21 months. The estimated 5-year overall survival and event-free survival was significantly better in the WT1-normal cohort (65% and 57% vs. 37% and 25%; P = .0003 and P < .0001, respectively) and 5-year cumulative incidence of relapse was significantly lower in the WT1-normal group (19% vs. 53%; P < .0001). Five-year non-relapse mortality was not significantly different (20% and 23%). Multivariate analysis revealed WT1-high expression and acute graft-versus-host disease grade 3/4 as significantly negative prognostic factors for OS. Overall, 49 patients developed WT1 molecular relapse in the post-transplant period; in 14 cases, the therapeutic intervention was done. In all but 1 relapsed patient where WT1 minimal residual disease (MRD) was monitored (38 patients), we detected WT1-high levels (sensitivity of 97%). CONCLUSION: The results of the analysis confirmed our previous experience that WT1 status before allo-HSCT is a strong prognostic factor for both OS and relapse risk. In addition, we confirmed the usefulness of this marker for MRD monitoring after allo-HSCT. The main advantage is the possibility of frequent MRD monitoring in peripheral blood and early bone marrow examination based on WT1-high expression.

Timing of Post-Transplantation Cyclophosphamide Administration in Haploidentical Transplantation: A Comparative Study on Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The timing of immunosuppressive therapy used in combination with post-transplantation cyclophosphamide (PTCY) in haploidentical hematopoietic stem cell transplant (haplo-HSCT) is not standardized. We evaluated the schedules of immunosuppression therapy after haplo-HSCT in 509 patients with acute leukemia receiving PTCY on days +3 and +4 along with tacrolimus (group 1; n = 215), with cyclosporine A (CSA) and mycophenolate mofetil (MMF) from day +5 (group 2; n = 170), or CSA + MMF from day 0 or 1 with PTCY on days +3 and +5 (group 3; n = 124). Compared with the other 2 groups, patients in group 3 were younger (median age, 46 years; P = .02) and more often received bone marrow (77%; P < .01) and a regimen containing thiotepa, fludarabine, and busulfan (84%; P< .01). At 2 years, overall survival was 44% was in group 1, 48% in group 2, and 59% in group 3 (P= .15); leukemia-free survival (LFS) was 43%, 46%, and 53% (P= .05); and refined graft-versus-host disease-free, relapse-free survival (rGRFS) was 33%, 39%, and 36% (P = .02). The incidence of grade II-IV acute GVHD was 25% in group 1, 39% in group 2, and 18% in group 3 (P< .01); incidence of chronic GVHD was 25%, 21%, and 24% (P= .50); relapse incidence was 36%, 37%, and 26% (P= .02); and nonrelapse mortality was 26%, 20%, and 21% (P= .35). On multivariate analysis, early start of immunosuppression therapy at day +1 followed by PTCY was associated with a better LFS (hazard ratio [HR], .58; P= .02) and improved rGRFS (HR, .62; P = .02). In this study, the timing of immunosuppression influenced the outcomes of haplo-HSCT with PTCY. An early start of CSA + MMF with PTCY administered on days +3 and +5 improves LFS and rGRFS.

Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for T Cell Acute Lymphoblastic Leukemia: A Report from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party.

Allogeneic hematopoietic cell transplantation (HCT) is recommended in high-risk patients with T cell acute lymphoblastic leukemia (T-ALL). For patients without an HLA-identical donor, haploidentical (haplo-) HCT is becoming the leading source of stem cell donation. However, data are scarce on predictive factors for outcome in that setting. We identified 122 adults (20% female; median age, 31 years; range, 18 to 68 years) with T-ALL who underwent haplo-HCT with post-transplantation cyclophosphamide (ptCy) between 2010 and 2017. The median duration of follow-up of living patients was 23 months. The 2-year incidences of relapse and nonrelapse mortality were 45% and 21%, respectively. The 2-year leukemia-free survival (LFS), overall survival (OS), and graft-versus-host disease, relapse-free survival (GRFS) were 34%, 42%, and 27%, respectively. The 2-year LFS and OS were highly influenced by disease status at transplantation, being 49% and 55%, respectively, for patients in first complete remission (CR1); 34% and 50%, respectively, for those in second CR (CR2); and 8% and 12%, respectively, for patients with active disease. On multivariate analysis, only disease status was found to affect LFS and OS. Transplantation in CR2 negatively affected LFS, whereas active disease at the time of haplo-HCT negatively affected LFS and OS. In conclusion, haplo-HCT with ptCy produced encouraging results in this challenging disease, particularly when performed in patients in CR. Despite the limitation of the small sample size, our results were not affected by the type of conditioning, calling into question the need for total body irradiation-based myeloablative conditioning in that setting.

Reduced intensity conditioning regimens including alkylating chemotherapy do not alter survival outcomes after allogeneic hematopoietic cell transplantation in chronic lymphocytic leukemia compared to low-intensity non-myeloablative conditioning.

PURPOSE: The optimal dose intensity for conditioning prior to allogeneic hematopoietic stem cell transplantation (alloHSCT) for chronic lymphocytic leukemia (CLL) is unknown. METHODS: We retrospectively compared outcomes of patients who received a first alloHCST after non-myeloablative (NMA) and reduced intensity conditioning (RIC). Data of 432 patients with a median age of 55 years were included, of which 86 patients underwent NMA and 346 RIC. RESULTS: The median follow-up after alloHSCT was 4.3 years. Compared to the RIC group, more NMA patients had purine-analog-sensitive disease, were in complete remission and received matched related donor transplantation. After RIC, the probabilities for 5-year OS, EFS, CIR, and NRM were 46%, 38%, 28%, and 35% and after NMA the respective probabilities were 52%, 43%, 25%, and 32%. In multivariate analysis, remission status prior to conditioning but not RIC versus NMA conditioning had a significant impact on CIR, EFS, and OS. CONCLUSION: Presumed higher anti-leukemic activity of RIC versus NMA conditioning did not translate into better outcomes after alloHSCT, but better remission status prior to conditioning did. Effective pathway inhibitor-based salvage therapies combined with NMA conditioning might thus represent the most attractive contemporary approach for alloHSCT for patients with CLL.

Myeloablative and Reduced-Intensity Conditioned Allogeneic Hematopoietic Stem Cell Transplantation in Myelofibrosis: A Retrospective Study by the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation.

This retrospective study by the European Society for Blood and Marrow Transplantation analyzed the outcome of 2224 patients with myelofibrosis (MF) who underwent allogeneic stem cell transplantation (allo-SCT) between 2000 and 2014; 781 (35%) underwent myeloablative conditioning (MAC) and 1443 (65%) reduced-intensity conditioning (RIC). Median patient age was 52.9 years (range, 18 to 74 years) and 57.5 years (range, 21 to 76 years) in the MAC and RIC cohorts, respectively. Donor type was similar: matched sibling donors (MAC, 317 [41%]; RIC, 552 [38%]) and unrelated donors (MAC, 464 [59%]; RIC, 891 [62%]). Median time to both neutrophil and platelet (>20 × 109/L) engraftment did not differ between cohorts. Rates of grade II to IV acute GVHD were 28% (MAC) and 31% (RIC; P = NS). Cumulative chronic GVHD rates (limited/extensive) were 22%/27% (MAC) and 19%/31% (RIC; P = .10). Cumulative incidences of nonrelapse mortality (NRM) at 1, 3, and 5 years were 25.5%, 32.2%, and 34.6% (MAC) and 26.3%, 32.8%, and 34.4% (RIC), respectively. There was a trend toward a higher relapse rate with RIC regimens compared with MAC (P = .08); rates at 1, 3, and 5 years were 10.9%, 17.2%, and 20.1% (MAC) and 14%, 19.7%, and 23.2% (RIC), respectively. No significant difference in 5-year probabilities of overall survival (OS) was noted: MAC (53.0%; 95% confidence interval [CI], 49.1% to 56.9%) and RIC (51.0%; 95% CI, 48.3% to 53.7%); P = .78. Regarding the composite end point of GVHD-free/relapse-free survival (GRFS), the unadjusted Kaplan-Meier estimate of 5-year GRFS was 32.4% (95% CI, 29.0% to 36.1%) in the MAC group and 26.1% (95% CI, 23.9% to 28.2%) in the RIC group (P = .001). In the MAC cohort, multivariable analysis confirmed worse OS and NRM with older age (>50 years), using an unrelated donor and a Karnofsky Performance Status of 80 or less. For the RIC cohort, worse OS and NRM were associated with age 60 to 70 years compared with younger recipients, use of a mismatched donor, and poor performance status. In conclusion, although similar OS rates existed for both cohorts overall, this study suggests that MAC should still be used for younger individuals suitable for such an approach due to a trend toward less relapse and an overall suggested advantage of improved GRFS, albeit this should be examined in a more homogeneous cohort. RIC allo-SCT still offers significant survival advantage in the older, fitter MF allograft patient, and optimization to reduce significant relapse and NRM rates is required.

Posttransplant cyclophosphamide vs antithymocyte globulin in HLA-mismatched unrelated donor transplantation.

The use of anti-thymocyte globulin (ATG) has represented the standard of care in graft-versus-host disease (GVHD) prophylaxis in patients undergoing a mismatched unrelated donor (MMUD) transplant. The safety and feasibility of posttransplant cyclophosphamide (PTCY) in this setting have been reported recently, but no study has compared the outcomes of PTCY vs ATG in 9/10 MMUD transplants. Using the registry data of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we performed a matched-pair analysis comparing those 2 strategies in a 9/10 MMUD setting. Ninety-three patients receiving PTCY were matched with 179 patients receiving ATG. A significantly lower incidence of severe acute GVHD was observed with PTCY compared with ATG. Recipients of the former also showed higher leukemia-free survival and GVHD/relapse-free survival (GRFS). When performing a subgroup analysis including patients receiving peripheral blood stem cells, being in complete remission, or receiving the same associated immunosuppressive agents, superiority of PTCY over ATG was confirmed. Similar to the haploidentical setting, use of PTCY is an effective anti-GVHD prophylaxis in the 9/10 MMUD transplant. Use of PTCY may also provide better outcomes in long-term disease control. These results need confirmation in large prospective randomized trials.

Hematopoietic Stem Cell Transplantation From Haploidentical Donors in Aplasia After Cladribine/Cytarabine Chemotherapy for Refractory Acute Myeloid Leukemia or Myelodysplastic Syndrome.

INTRODUCTION: Survival rate of patients with chemorefractory acute myeloid leukemia (AML) or myelodysplastic syndrome with excess blasts (MDS-EB) is poor. Allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy in these patients. PATIENTS AND METHODS: We report a retrospective analysis of outcomes of therapy of 24 patients with AML or MDS-EB refractory to high-dose salvage chemotherapy or who had failed previous HCT, who received T-cell-replete HLA haploidentical HCT in aplasia after cladribine/cytarabine-based chemotherapy followed by reduced intensity or myeloablative conditioning. All patients had active disease before commencement of the treatment. RESULTS: Of the patients, 91.7% achieved complete remission (CR), whereas 2 patients (8.2%) died in aplasia. One-year relapse rate was 49.3%. Cumulative incidence of nonrelapse mortality (NRM) was 25.6%. In a subgroup of patients with HCT-comorbidity index score ≤ 3, NRM was 15.4%. Two-year overall survival and relapse-free survival were 30.6% and 22.6%, respectively. Incidence of grade 3 and 4 acute graft versus host disease was 21.3% and 8.3, respectively. CONCLUSION: We found that sequential therapy with HCT in aplasia after cladribine/cytarabine chemotherapy is feasible, results in high CR rates, and has acceptable toxicity profile; however, posttransplant relapse is common in patients treated with active disease.

Long-term outcome after allogeneic hematopoietic cell transplantation for myelofibrosis.

Allogeneic hematopoietic stem cell transplant remains the only curative treatment for myelofibrosis. Most post-transplantation events occur during the first two years and hence we aimed to analyze the outcome of 2-year disease-free survivors. A total of 1055 patients with myelofibrosis transplanted between 1995 and 2014 and registered in the registry of the European Society for Blood and Marrow Transplantation were included. Survival was compared to the matched general population to determine excess mortality and the risk factors that are associated. In the 2-year survivors, disease-free survival was 64% (60-68%) and overall survival was 74% (71-78%) at ten years; results were better in younger individuals and in women. Excess mortality was 14% (8-21%) in patients aged <45 years and 33% (13-53%) in patients aged ≥65 years. The main cause of death was relapse of the primary disease. Graft-versus-host disease (GvHD) before two years decreased the risk of relapse. Multivariable analysis of excess mortality showed that age, male sex recipient, secondary myelofibrosis and no GvHD disease prior to the 2-year landmark increased the risk of excess mortality. This is the largest study to date analyzing long-term outcome in patients with myelofibrosis undergoing transplant. Overall it shows a good survival in patients alive and in remission at two years. However, the occurrence of late complications, including late relapses, infectious complications and secondary malignancies, highlights the importance of screening and monitoring of long-term survivors.

Family Mismatched Allogeneic Stem Cell Transplantation for Myelofibrosis: Report from the Chronic Malignancies Working Party of European Society for Blood and Marrow Transplantation.

This analysis included 56 myelofibrosis (MF) patients transplanted from family mismatched donor between 2009 and 2015 enrolled in the European Society for Blood and Marrow Transplantation database. The median age was 57years (range, 38 to 72); 75% had primary MF and 25% had secondary MF. JAK2 V617F was mutated in 61%. Donors were HLA mismatched at 2 or more loci. Stem cells were sourced from bone marrow in 66% and peripheral blood in 34%. The median CD34+ cell dose was 4.8 × 106/kg (range, 1.7 to 22.9; n = 43). Conditioning was predominantly myeloablative in 70% and reduced intensity in the remainder. Regimens were heterogeneous with thiotepa, busulfan, fludarabine, and post-transplant cyclophosphamide used in 59%. The incidence of neutrophil engraftment by 28days was 82% (range, 70% to 93%), at a median of 21days (range, 19 to 23). At 2years the cumulative incidence of primary graft failure was 9% (95% CI 1% to 16%) and secondary graft failure was 13% (95% CI 4% to 22%). The cumulative incidence of acute graft-versus-host disease (GVHD) grades II to IV and III to IV was 28% (95% CI 16% to 40%) and 9% (95% CI 2% to 17%) at 100days. The cumulative incidence of chronic GVHD at 1 year was 45% (95% CI 32% to 58%), but the cumulative incidence of death without chronic GVHD by 1 year was 20% (95% CI 10% to 31%). With a median follow-up of 32 months, the 1- and 2-year overall survival was 61% (95% CI 48% to 74%) and 56% (95% CI 41% to 70%), respectively. The 1- and 2- year progression-free survival was 58% (95% CI 45% to 71%) and 43% (95% CI 28% to 58%), respectively, with a 2-year cumulative incidence of relapse of 19% (95% CI 7% to 31%). The 2-year nonrelapse mortality was 38% (95% CI 24% to 51%). This retrospective study of MF allo-SCT using family mismatched donors demonstrated feasibility of the approach, timely neutrophil engraftment in over 80% of cases, and acceptable overall and progression-free survival rates with relapse rates not dissimilar to the unrelated donor setting. However, strategies to minimize the risk of graft failure and the relatively high nonrelapse mortality need to be used, ideally in a multicenter prospective fashion.

Late treatment-related mortality versus competing causes of death after allogeneic transplantation for myelodysplastic syndromes and secondary acute myeloid leukemia.

The causes and rates of late patient-mortality following alloHCT for myelodysplastic syndromes or secondary acute myeloid leukemia were studied, to assess the contribution of relapse-related, treatment-related, and population factors. Data from EBMT on 6434 adults, who received a first alloHCT from January 2000 to December 2012, were retrospectively studied using combined land-marking, relative-survival methods and multi-state modeling techniques. Median age at alloHCT increased from 49 to 58 years, and the number of patients aged ≥65 years at alloHCT increased from 5 to 17%. Overall survival probability was 53% at 2 years and 35% at 10 years post-alloHCT. Survival probability at 5 years from the 2-year landmark was 88% for patients <45-year old and 63% for patients ≥65-year old at alloHCT. Cumulative incidence of nonrelapse mortality (NRM) for patients <45-year old at transplant was 7% rising to 25% for patients aged ≥65. For older patients, 31% of NRM-deaths could be attributed to population mortality. Favorable post-alloHCT long-term survival was seen; however, excess mortality-risk for all age groups was shown compared to the general population. A substantial part of total NRM for older patients was attributable to population mortality, information which aids the balanced explanation of post-HCT risk and helps improve long-term care.

Outcome of patients with Myelofibrosis relapsing after allogeneic stem cell transplant: a retrospective study by the Chronic Malignancies Working Party of EBMT.

Allogeneic Haematopoietic Stem Cell Transplant (allo-HSCT) remains the only curative approach for Myelofibrosis (MF). Scarce information exists in the literature on the outcome and, indeed, management of those MF patients who relapse following transplant. We hereby report on the management and outcome of 202 patients who relapsed post allo-HSCT for MF.

T-cell replete haploidentical stem cell transplantation attenuates the prognostic impact of FLT3-ITD in acute myeloid leukemia: A report from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Acute myeloid leukemia (AML) patients harboring the FLT3-ITD mutation are considered a high risk patient subset preferentially allocated for allogeneic stem cell transplantation in first remission. Whether FLT3-ITD retains a prognostic role in haploidentical stem cell transplantation (haplo-SCT) is unknown. To analyze the prognostic impact of FLT3-ITD in haplo-SCT, we performed a retrospective analysis of the multicenter registry of the acute leukemia working party of the European Society for Blood and Marrow Transplantation. We included all adult AML patients with known FLT3 status who underwent a first T-cell replete related haplo-HCT in first complete remission from 2005 to 2016. We evaluated 293 patients of whom 202 were FLT3wt and 91 were FLT3-ITD mutated. FLT3-ITD patients were more likely to be NPM1 mutated as well as be in the intermediate risk cytogenetic risk category. In multivariate analysis, patients with FLT3-ITD had comparable rates of relapse incidence [Hazard ratio (HR) = 1.34, confidence interval (CI) 95%, 0.67-2.7; P = .9] and leukemia-free survival (HR = 0.99, CI 95%, 0.62-1.57; P = .9) to those of FLT3wt patients. Overall survival, the incidence of nonrelapse mortality, and graft versus host disease-free/relapse-free survival were not significantly impacted by FLT3-ITD status. Furthermore, relapse and overall survival were comparable between FLT3-ITD patients transplanted from various donor pools, namely matched siblings, unrelated donors, haplo-SCT). Finally, subset analysis of patients with intermediate risk cytogenetics confirmed the absence of a prognostic impact of FLT3-ITD also for this patient segment. In AML patients undergoing T-cell replete haplo-SCT, the FLT3-ITD mutation possibly does not retain its prognostic significance.

Antimicrobial Resistance in Gram-Negative Rods Causing Bacteremia in Hematopoietic Stem Cell Transplant Recipients: Intercontinental Prospective Study of the Infectious Diseases Working Party of the European Bone Marrow Transplantation Group.

BACKGROUND: This intercontinental study aimed to study gram-negative rod (GNR) resistance in hematopoietic stem cell transplantation (HSCT). METHODS: GNR bacteremias occurring during 6 months post-HSCT (February 2014-May 2015) were prospectively collected, and analyzed for rates and risk factors for resistance to fluoroquinolones, noncarbapenem anti-Pseudomonas ß-lactams (noncarbapenems), carbapenems, and multidrug resistance. RESULTS: Sixty-five HSCT centers from 25 countries in Europe, Australia, and Asia reported data on 655 GNR episodes and 704 pathogens in 591 patients (Enterobacteriaceae, 73%; nonfermentative rods, 24%; and 3% others). Half of GNRs were fluoroquinolone and noncarbapenem resistant; 18.5% carbapenem resistant; 35.2% multidrug resistant. The total resistance rates were higher in allogeneic HSCT (allo-HSCT) vs autologous HSCT (auto-HSCT) patients (P < .001) but similar in community-acquired infections. Noncarbapenem resistance and multidrug resistance were higher in auto-HSCT patients in centers providing vs not providing fluoroquinolone prophylaxis (P < .01). Resistance rates were higher in southeast vs northwest Europe and similar in children and adults, excluding higher fluoroquinolone- and ß-lactam/ß-lactamase inhibitor resistance rates in allo-HSCT adults. Non-Klebsiella Enterobacteriaceae were rarely carbapenem resistant. Multivariable analysis revealed resistance risk factors in allo-HSCT patients: fluoroquinolone resistance: adult, prolonged neutropenia, breakthrough on fluoroquinolones; noncarbapenem resistance: hospital-acquired infection, breakthrough on noncarbapenems or other antibiotics (excluding fluoroquinolones, noncarbapenems, carbapenems), donor type; carbapenem resistance: breakthrough on carbapenem, longer hospitalization, intensive care unit, previous other antibiotic therapy; multidrug resistance: longer hospitalization, breakthrough on ß-lactam/ß-lactamase inhibitors, and carbapenems. Inappropriate empiric therapy and mortality were significantly more common in infections caused by resistant bacteria. CONCLUSIONS: Our data question the recommendation for fluoroquinolone prophylaxis and call for reassessment of local empiric antibiotic protocols. Knowledge of pathogen-specific resistance enables early appropriate empiric therapy. Monitoring of resistance is crucial. CLINICAL TRIALS REGISTRATION: NCT02257931.

Baseline Characteristics Predicting Very Good Outcome of Allogeneic Hematopoietic Cell Transplantation in Young Patients With High Cytogenetic Risk Chronic Lymphocytic Leukemia - A Retrospective Analysis From the Chronic Malignancies Working Party of the EBMT.

BACKGROUND: Patients with genetically high-risk relapsed/refractory chronic lymphocytic leukemia have shorter median progression-free survival (PFS) with kinase- and BCL2-inhibitors (KI, BCL2i). Allogeneic hematopoietic stem cell transplantation (alloHCT) may result in sustained PFS, especially in younger patients because of its age-dependent non-relapse mortality (NRM) risk, but outcome data are lacking for this population. PATIENTS AND METHODS: Risk factors for 2-year NRM and 8-year PFS were identified in patients < 50 years in an updated European Society for Blood and Marrow Transplantation registry cohort (n = 197; median follow-up, 90.4 months) by Cox regression modeling, and predicted probabilities of NRM and PFS of 2 reference patients with favorable or unfavorable characteristics were plotted. RESULTS: Predictors for poor 8-year PFS were no remission at the time of alloHCT (hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.1-2.5) and partially human leukocyte antigen (HLA)-mismatched unrelated donor (HR, 2.8; 95% CI, 1.5-5.2). The latter variable also predicted a higher risk of 2-year NRM (HR, 4.0; 95% CI, 1.4-11.6) compared with HLA-matched sibling donors. Predicted 2-year NRM and 8-year PFS of a high cytogenetic risk (del(17p) and/or del(11q)) patient in remission with a matched related donor were 12% (95% CI, 3%-22%) and 54% (95% CI, 38%-69%), and for an unresponsive patient with a female partially HLA-matched unrelated donor 37% (95% CI, 12%-62%) and 38% (95% CI, 13%-63%). CONCLUSION: Low predicted NRM and high 8-year PFS in favorable transplant high cytogenetic risk patients compares favorably with outcomes with KI or BCL2i. Taking into account the amount of uncertainty for predicting survival after alloHCT and after sequential administration of KI and BCL2i, alloHCT remains a valid option for younger patients with high cytogenetic risk chronic lymphocytic leukemia with a well-HLA-matched donor.